Geiger-O Open Conda and activate the TTS environment, then try the following command:
pip install transformers==4.57.1
This may resolve the issue.
If it doesn't, try installing coqui-tts instead of coqui-tts[languages] (you won't be able to use Japanese/Chinese languages though):
pip install coqui-tts
If this still doesn't work, could you please tell me which GPU you use, on which system, and if you know, your CUDA version?
I've also updated the repo yesterday with a brand-new version of the TTS server. You can try a fresh installation by using the "Unified Server" by clicking the install.bat file. This is still a WIP and being tested, though.